How Strong Is Your Heart?

The Bruce Protocol Treadmill test is mainly used for evaluating cardiac fitness and function. This test was designed by Dr Robert Bruce in 1963 and was initially used for assessing patients with heart diseases. This test is a very popular way of testing V ∙O2 max, which is closely related to aerobic endurance. This test requires that the person run for as long as possible on a treadmill. The treadmill speed and incline increase in specific increments at timed intervals.

Each interval is three minutes long, and at the end of each interval, the speed and incline of the treadmill are increased until the person can no longer complete the exercise.

Here is the procedure:

Before exercise begins, measure resting heart rate, either manually or using a heart rate monitor (see the sidebar Measuring Your Heart Rate for more information).

Warm your body up by walking on the treadmill at a very slow speed of 1.5 to 1.7 miles per hour (2.4 to 2.7 km/h) for three to five minutes. Do not hold on to the handrails while performing this test.

Begin the test by setting the treadmill speed at 1.7 miles per hour (2.7 km/h)or at an incline of 10 percent.

At every three-minute interval, increase treadmill speed and incline by 2 percent, as follows:

Interval 1: 10% incline at 1.7 mph (2.4 km/h)

Interval 2: 12% incline at 2.5 mph (4 km/h)

Interval 3: 14% incline at 3 mph (4.8 km/h)

Interval 4: 16% incline at 4 mph (6.4 km/h)

Interval 5: 18% incline at 4.5 mph (7.2 km/h)

Interval 6: 20% incline at 5 mph (8 km/h)

Interval 7: 22% incline at 5.5 mph (8.9 km/h)

Interval 8: 24% incline at 6 mph (9.7 km/h)

Interval 9: 26% incline at 6.5 mph (10.46 km/h)

Interval 10: 28% incline at 7 mph (11.3 km/h)

Stop the test when you are unable to continue, or your heart rate exceeds 85 percent of your maximal heart rate, using the 220 – your age formula provided previously.

Cool down for three to five minutes, or until your heart rate reaches 100 bpm or lower.

Because the Bruce Protocol Treadmill Test attempts to get you to reach almost maximal levels of intensity, you have to run continuously until you are too tired to continue. V ∙ O2 max is then calculated by entering the total time on the treadmill into a formula

(e.g., 9 minutes and 30 seconds is entered into the formula as 9.5).

The formula for women is as follows:

4.38 × ____ (time) – 3.9 = V ∙ O2max

Using 9 minutes and 30 seconds again as an example, the calculation would be as follows: